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A112668 Triangle read by rows: row n gives an n-term geometric progression with first term 1 such that the sum of the n terms is a multiple of n. 4
1, 1, 3, 1, 4, 16, 1, 3, 9, 27, 1, 6, 36, 216, 1296, 1, 5, 25, 125, 625, 3125, 1, 8, 64, 512, 4096, 32768, 262144, 1, 3, 9, 27, 81, 243, 729, 2187, 1, 4, 16, 64, 256, 1024, 4096, 16384, 65536, 1, 9, 81, 729, 6561, 59049, 531441, 4782969, 43046721, 387420489, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..56.

EXAMPLE

1

1 3

1 4 16

1 3 9 27

1 6 36 216 1296

1 5 25 125 625 3125

...

MAPLE

A112668 := proc(n) local a2, i, a ; a2 := 2 ; while (1-a2^n)/(1-a2) mod n <> 0 do a2 := a2+1 ; od ; a := [] ; for i from 1 to n do a := [op(a), a2^(i-1)] ; od ; RETURN(a) ; end: for row from 1 to 14 do r := A112668(row) : for n from 1 to nops(r) do printf("%d, ", op(n, r)) ; od : od : # R. J. Mathar, Mar 13 2007

CROSSREFS

Cf. A110737, A110738, A110739.

Sequence in context: A066712 A064809 A058361 * A016734 A272473 A125846

Adjacent sequences:  A112665 A112666 A112667 * A112669 A112670 A112671

KEYWORD

easy,nonn,tabl

AUTHOR

Amarnath Murthy, Aug 10 2005

EXTENSIONS

More terms from R. J. Mathar, Mar 13 2007

STATUS

approved

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Last modified October 1 17:45 EDT 2020. Contains 337444 sequences. (Running on oeis4.)